PORTSMOUTH — Many shelves were empty at the Woodbury Avenue Market Basket on Sunday, but employees were full of moxie to fight for the return of their former leader, Arthur T. Demoulas.

The company's warehouse workers and drivers are refusing to ship products to stores, which resulted in bare shelves at Market Basket locations over the weekend. Customers had looks of confusion as they gazed upon aisles with empty shelves that they expected to be filled with products such as apples, celery and steak.

If they didn't know about the Market Basket community's shared passion for Demoulas' leadership, they do now.

"He makes this such a great place to work in because of how he treats the customers, and how he treats us," 17-year-old cashier Keeley Van Bramer said of Demoulas. "We need to support him and bring him back."

Employees of the New England grocery store chain are rallying behind the former chief executive officer, who was fired last month and replaced with co-chief executives Felicia Thornton and James Gooch.

The Market Basket work force issued an ultimatum to the company's board to reverse the decision, which did not happen. Now Demoulas' faithful followers from the corporate office down to cashiers are fighting back with protests, petitions and walkouts.

Employees at store locations face a threat from the new chief executive officers to fire any worker who misses a shift in protest.

On Sunday, the company fired several employees, including a supervisor at the company's Tewksbury warehouse, Dean Joyce, who had been a loud voice in the employee revolt, according to the protesters' Web site, wearemarketbasket.com. The other terminations included more supervisors and buyers, the Web site says.

Most of the company's 25,000 workers are reporting for duty, but many are informing customers about the direction they think the company should be going in. The workers are presenting petitions for Demoulas' return while wearing T-shirts with his face that say "I Believe."

Also on Sunday, some store employees refused to unload tractor-trailers driven by replacement drivers as part of the protests.

"This is for both employees and customers," 17-year-old cashier Jordan Fletcher said of the protests. "We want customers to have the better end of the business and better prices."

Many employees say the new leadership is less focused on continuing good business practices that benefit workers and customers, and more concerned about fattening their own wallets. They say Demoulas encouraged a worker- and customer-friendly business environment for the chain of 71 supermarkets.

"What (Demoulas) does is more family-oriented," Van Bramer said. "He treats us so well and gives us a great place to work at. We need to support him and bring him back."

Bill Beaulieu works as a manager at the Portsmouth location, and he could be seen talking to befuddled customers in front of empty shelves late Sunday.

He explained that Demoulas is the "real deal" and had devoted his life to the company and its employees. Not only that, the longtime chief executive officer had always shown interest in the personal lives and concerns of those he led, Beaulieu said.

Many customers showed the same dedication to maintaining that culture at Market Basket, especially when it brings great customer service and low prices. They are even answering the call of some local lawmakers to boycott the grocery chain unless Demoulas is reinstated.

Some customers said that they do not believe in the leadership of his cousin, Arthur S. Demoulas, who recently took control of the company's board after decades of internal squabbling.

Jamie Belilah of Portsmouth said she is concerned the new leadership is too focused on profits for the higher-ups in the company.

"We have to think a little bit less about making giant amounts of money and more about our community," she said. "It is not about who has the deepest pockets, it is about having good communities and having good, quality places to buy my stuff. We better not lose this."

Susan Stewart of Dover has been a loyal Market Basket shopper since 1988 and fully supports the effort to restore the company's ousted leader. "I just think they should do what's in their hearts and that is exactly what they are doing," she said of the protesting workers. "Good for them."

Maureen Bunce of Eliot, Maine, was surprised to see so many empty shelves on Sunday, but she said sacrifices will be necessary to keep her favorite supermarket's "excellent service, prices and employee-friendly policies."

"It has been a great service for our community," she said.

While they are dedicated to the fight, many of the employees were nervous about their job security during the current wave of protests. That unease is not stopping most of them because they share the belief that Market Basket's values keep customers coming back.

"We are all willing to put everything we have into this," Van Bramer said. "If (our shelves) have to go completely bare, we will go completely bare. We are really hoping it works. Why are people going to shop here if we don't have what they need?"